Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows from Operating Activities
Net Income	$ 2,077	$ 2,094	$ 1,478
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	585	588	597
Realized investment (gains) losses	(57)	(154)	(213)
Deferred income taxes	21	(22)	197
Net changes in assets and liabilities, net of non-operating effects:
Premiums, accounts and notes receivable	(945)	(780)	(110)
Reinsurance recoverables	55	22	369
Deferred policy acquisition costs	(182)	(176)	(227)
Other assets	16	(265)	405
Insurance liabilities	657	457	1,040
Accounts payable, accrued expenses and other liabilities	423	202	(483)
Current income taxes	(25)	111	(56)
Loss on extinguishment of debt	100	0	0
Cash used to exit run-off reinsurance business	0	0	(2,196)
Other, net	(8)	(83)	(82)
Net cash provided by / (used in) operating activities	2,717	1,994	719
Proceeds from investments sold:
Fixed maturities and equity securities	1,555	1,769	1,775
Investment maturities and repayments:
Fixed maturities and equity securities	1,435	1,640	1,621
Commercial mortgage loans	640	453	653
Other sales, maturities and repayments (primarily short-term and other long-term investments)	1,297	2,706	1,661
Investments purchased or originated:
Fixed maturities and equity securities	(4,234)	(5,424)	(3,062)
Commercial mortgage loans	(500)	(287)	(58)
Other (primarily short-term and other long-term investments)	(1,183)	(2,115)	(1,930)
Property and equipment purchases	(510)	(473)	(527)
Acquisitions, net of cash acquired	(99)	0	(76)
Other, net	0	(24)	(42)
Net cash provided by/ (used in) investing activities	(1,599)	(1,755)	15
Cash Flows from Financing Activities
Deposits and interest credited to contractholder deposit funds	1,429	1,482	1,399
Withdrawals and benefit payments from contractholder deposit funds	(1,359)	(1,456)	(1,358)
Net change in short-term debt	(21)	(112)	(101)
Net proceeds on issuance of long-term debt	894	0	0
Repayment of long-term debt	(938)	0	(15)
Repurchase of common stock	(671)	(1,612)	(1,003)
Issuance of common stock	154	110	150
Other, net	(18)	6	(2)
Net cash provided by / (used in) financing activities	(530)	(1,582)	(930)
Effect of foreign currency rate changes on cash and cash equivalents	(40)	(32)	13
Net increase (decrease) in cash and cash equivalents	548	(1,375)	(183)
Cash and cash equivalents, January 1	1,420	2,795	2,978
Cash and cash equivalents, December 31	1,968	1,420	2,795
Supplemental Disclosure of Cash Information:
Income taxes paid, net of refunds	1,194	1,085	519
Interest paid	$ 245	$ 259	$ 265